


Something in the Water

by coeurvolant



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Alternate Universe, F/F, F/M, Hurt/Comfort, Romance
Language: English
Status: In-Progress
Published: 2019-09-01
Updated: 2019-09-01
Packaged: 2020-10-05 00:09:29
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,444
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20479730
Author URL: https://archiveofourown.org/users/coeurvolant/pseuds/coeurvolant
Summary: "Are you here to kill me?" The girl asked quietly, something akin to peace in her eyes. "Are you the Goddess, answering my prayers?"Byleth furrowed her eyebrows, "No, I work for the kingdom." She said vaguely. "Were you praying to the Goddess just now?""...Every day." The girl admitted, not making a move to struggle or escape.an AU in which Byleth may have failed her mission, but she finds something else instead.





	Something in the Water

**Author's Note:**

> Very loosely based on Three Houses plot, spoilers from BE gameplay, Marianne's paralogue and support convos

"Byleth." The dark haired woman blinked as she heard her name being repeated impatiently from the younger girl beside her, smiling apologetically as she turned her attention back to her ruler.

  
"Sorry. What were you saying?" She asked, not bothering to feign acknowledgement of the conversation that had supposedly been occurring for the past several minutes between the two. They were much past such formalities, after all.

  
"I was _saying_, the beast takes multiple forms, or so we've heard. But the only sure piece of information we have is that it is the sole creature that is enclosed within that tower, so you must eliminate whatever -_whomever_ you find inside. Even if it takes the form of one you hold dear to yourself." Edelgard said seriously, all irritation gone as she briefed Byleth on her mission. "The lives of our people depend on you now. Do not come back if you plan to fail."

  
Byleth gave her a lopsided smile, resisting the urge to pat the Emperor on the head as she always did when they were much younger. Although they were alone and working quite discreetly undercover, there were still boundaries to be drawn between their social standings. "I won't fail you, El." She said, stretching her arms leisurely as she hopped to her feet and surveyed her surroundings. "I'll take to the rooftops. Meet you back at your place before the break of dawn." She said, saluting the younger girl as she gripped the hilt of her blade and pulled the hood of her cape over her head, holding onto its outer edges with her free hand so to obscure her face as she raced atop the establishments that surrounded the kingdom.

  
From a distance, she was just a streak of darkness, a shadowy whisper that didn't warrant the attention of anyone who happened to catch note of her very existence.  
  
Byleth had been called many things in her life; a mercenary, a professor, a thief, and more recently, an assassin. She was the Emperor's famed right hand woman -seldom seen by the public eye, that was more Hubert's role -doing Edelgard's dirty work from the background as Hubert took a more...open approach to intimidation. Edelgard was a fair ruler, a good one, by all means, serving her people more than they served herself. But it was without say that there were some issues that even the restraints of the law and supervision of kingdom's upholding soldiers could not resolve.

  
This was where Byleth stepped in. Her carefree nature, her rather innocent features and blank expression; she was, by all means, not nearly as intimidating or fierce as Hubert or Edelgard looked. She did not possess a commanding aura as they did, and neither did she possess any particular oratory skills that would otherwise convince someone she might have at some point. And so once Edelgard had been crowned the Emperor, Byleth chose to operate from behind alongside Hubert. She was tired after the war against the Church of Seiros, after all, and she could do without the attention. Most people thought she had perished after the battle and she strongly believed it was better that way.  
  
  
Byleth continued her quiet steps towards her destination, a towering dark fortress overgrown with vines and moss. It was at the very edge of the Eastern territory of Fodlan, mostly overlooked as it was the greatest distance away from Edelgard's rule. The emperor, however, had insisted on accompanying Byleth this far, perhaps a part of the young ruler yearning for the adventures the two used to have during more carefree days. But now Byleth found herself standing alone in front of Margrave Edmund's tower, a prison encampment which was rumored to keep an accursed beast within. It was an old tale that did not catch the attention of the kingdom until recently. There was talk amongst the villagers that the beast had been somehow escaping at night, slaughtering farm animals and innocent people who wandered too far after curfew, before returning back to the tower before the break of dawn. Whenever Edelgard had brought the topic up to Margrave Edmund during his visits in the past, he had merely laughed if off, subtly chiding the people for believing such an old wives' tale. 

The villagers, however, had been insistent upon spreading the tale of a shapeshifter, capable of luring anyone in by taking the appearance of a deceased loved one. The rumors had spread until Edelgard was discreetly asked by the nobles of Margravate Edmund, each too fearful of being under the scrutiny of the great Margrave Edmund to resolve it between themselves. Edelgard had listened, considered, and observed the occurrences before formally dispatching Byleth.

  
It no longer mattered whether the tale was true or false -the villagers were being harmed and discord was upon the Eastern province. Order had to be regained, and both Edelgard and Hubert had been given reason beyond doubt to believe that there was, indeed, some sort of malevolent beast that was kept within the fortress. It wouldn't be the first time such a tale turned out to be true. The young ruler's initial hesitance had only been the fact that there was no evidence of a _shapeshifting _beast capable of turning into multiple forms having ever existed, and further more, no reason for such a powerful figure as Margrave Edmund to be holding one hostage. Unless it were for sinister purposes, which would be another problem in itself.

  
And so now Byleth found herself scaling up the walls, thankful for her grappling hook and the vines that seeped out from between the bricks as she found herself slipping more often than she would like over the slick moss that stuck to the tower like a plague. She didn't dare pause out of fear of losing her footsteps and disappointing Edelgard -she would rather be found dead than fail her Emperor, but it sure would raise questions if a supposed former tutor of the Emperor had been found dead upon the base of Margrave Edmund's tower. People would surely start suspecting _her_ to be the beast.

  
With that in mind, Byleth continued climbing, focusing on the distance in front of her instead of what remained below. The closer she climbed up the walls, the more silent the air became, as though whatever was within was anticipating her arrival. The very thought made Byleth nervous enough to pause her endeavors for a few brief moments, listening to closely for any discernible sound as she tried in vain to ignore the pounding of her own heart within her ears.

  
She finally arrived at the lone window of the tower, pulling herself up with a single hand as she poked her head up through the gap and peered through the darkness. It was a rather small room, sparsely furnished. There was soft breathing in the corner of the room, where a lone figure laid underneath the covers across from a small door which she assumed led to the washroom. With deft hands, Byleth quietly secured her grappling hook so that the top remained latched to the window while the roped dangled down, allowing her for a quick escape if needed. She took another long look at her surroundings before she jumped down silently, her seasoned footsteps light upon even the cold, bricked floor. It had been about a ten foot drop, the protesting of her ankles only at the very depths of her mind as she continued moving towards her target.

  
Byleth whispered a brief prayer as she unsheathed her dagger, gripping its blade tightly against her palm as she approached the sleeping figure -she feared what it may transform in to. Her father, Jeralt? Her mother, whom she never knew? There were endless possibilities and a part of her yearned to see, to speak with someone who held some sort of thread to her unknown past, be it fiction or not. She would have even gladly greeted Rhea's presence once more, even if it were only to kill her again.

  
Her determined mind made up, she swung herself over the figure on the bed, knees locked onto either side of the person's body as she pressed her sharp blade to their abdomen. With her free hand, she ripped the covers roughly over the person's head, eyes blinking in surprise as an unfamiliar face stared fearfully back.  


  
It was a girl, around her age. With striking maya blue hair and mournful eyes that Byleth would have been sure to remember if she had ever seen them before, the assassin felt a a rush of disappointment as she realized the rumors were likely false.

  
"Are you the beast?" She asked, a hint of irritation upon her tongue as she looked the girl over. She was pretty, she'd admit it -possibly even more so than her beloved Emperor, but the letdown in not being able to set eyes upon a deceased one linked to her past had settled over her cloudy mind.

  
"Are you here to kill me?" The girl asked back quietly, something akin to peace in her eyes. "Are you the Goddess, answering my prayers?"

  
Byleth furrowed her eyebrows, "No, I work for the kingdom." She said vaguely. She supposed if she was to kill this girl anyways, it wouldn't matter what information she gave her. "Were you praying to the Goddess just now?"

  
"...Every day." The girl admitted, not making a move to struggle or escape. she closed her eyes peacefully once more as her brows furrowed in discomfort, "Please, just make it quick." She whispered.

  
"Alright," Byleth agreed, gripping the dagger in her hand tighter as she traced the blade to rest over the stranger's heart, "Why don't you show your true form?" She murmured, curiosity getting the better of her actions. Perhaps there was a chance for her to see something new, after all. 

  
"It doesn't happen every night." The girl sighed, her hands now clasped tightly against her covers as she awaited her impending doom.

  
Byleth readjusted her grip, her eyes flickering back and forth between the blade to the girl's furrowed eyebrows. She had never felt such hesitation before, and she was unsure why. Was it because some part of her didn't believe such a girl could be the monstrous beast the villagers were making her out to be? Or was it her determination to be brought back to the past that she had given up on all those years ago?

  
"Prove it." She said instead, bringing her dagger away as she sat back on her heels, "Prove that you're the beast. I'll feel a lot better than disposing of you that way."

  
"No!" The girl exclaimed indignantly, looking shocked herself at how loudly her voice had carried in her panic, as she sat up in her bed. "I...I can't do that. I won't." She said firmly, fear in her now open eyes as she glanced at the window that led to the outside.

  
Byleth could see the dark bags underneath the girl's weary eyes as she looked uneasily towards her only source of escape. The girl shuddered for a brief, unnatural moment before she clamped her hands together vigorously, a string of low prayers flowing out of her mouth instinctively as she curled in upon herself.

  
"Please, if you're going to kill me, do it now." The girl pleaded between her prayers, shuddering again more violently as she was tossed to her side. Byleth jumped off the bed at this point, sheathing her dagger to instead bring out the much larger sword she had strapped to her back and holding it menacingly towards the girl. She used the Sword of the Creator rarely, as she feared it would one day break, but a situation like this one seemed to call for it. She watched the scene unfold in front of her with observant eyes, never once allowing her shoulders to fall from their tensed position.

  
The blue haired girl rolled off the bed and to her knees at this point, a darkness pouring over her body as she cried out in pain. It was as though all the shadows in the room had gathered beneath her, pulling her frail body into their depths as she shouted in protests. Byleth remained still, taking deep breaths as she prepared herself for the battle to come -she convinced herself that she would feel a lot better about executing the girl after seeing the monster she was capable of turning into.  
  
  
"Please," A voice begged from within the shadows, its voice garbled and haunting, "Please, help...me...please," Byleth faltered as she stood back, shock in her blue eyes as the shape rose to its feet, the tips of its wolf-like ears brushing up against the very pointed top of the tower. Pieces of debris fell around them unlike ashen snow as it let out a deafening howl.  
  
The beast lunged at her without warning, slamming a large paw onto the assassin's shoulder as it continued crying in its own personal agony. Byleth stifled a scream of her own, feeling the bones within her shoulder crack under the creature's uncaring weight. She used her heeled boots to kick into its chest, strengthening her resolve enough to bear her blade against the beast once more.The large creature remained in the corner of the room this time, letting out small whimpers as it looked at her with pained eyes. Byleth muttered another brief prayer as she braced her sword to eye level, the pointed tip directed at the beast.

With a shout she charged at it, driving her blade through its chest as she felt the warmth of the creature's blood pool over herself. She let out a gasp of surprise as the impact seemed to cause the creature's body to implode on itself, the fur washing away into a crimson liquid that gathered at the ground beneath her. Byleth wiped her eyes with the edge of her cape as she took a shaky breath in, walking towards the girl who now laid in the center of the creature's blood. "I can't die unless you kill me in my original form." She said, her voice hoarse and laced with anguish as she clutched at her chest.

  
"But you still feel the pain?" Byleth asked rhetorically as she knelt beside the girl. "What is your name?"

  
"...M-Marianne." The girl whispered between her wheezing gasps, the pool of blood behind her dissolving rapidly as it became absorbed into the shadowy earth below.

  
Byleth discarded her sword as she lifted the girl's chin with a shaking hand, "I'm going to save you, Marianne."  
  
  
  


**Author's Note:**

> Thought of this really late at night and scribbled it down...I'm the worst at writing action scenes....


End file.
